I remember there was a post on here several years ago (maybe the first time the subject came up) from someone with a European Wave. The tiller arms on their version were WAY shorter, like only one foot; but the boats came standard with a tiller extension. The poster said their Waves would be un-sailable without the extension. He posted a photo of his boat with snow on it, showing the short arms with the extension; and people joked about the white sand.

Perhaps the IHCA and IWCA could use their configuration as a reference (if they are truly "International").

Edit: I found the post, but I don't know how to imbed it. From "2006 Draft IWCA Class Rules" thread on 11/4/06 by "Bengtos" from Stockholm. Here's the photo.